The use of so-called voice mail message services in a communications (cellular) network is known. Voice mail message services enable users of radiotelephones (also referred to as user terminals or mobile terminals or stations), to receive voice messages left by calling parties when, by example, the user terminal is powered off or is otherwise not available, or if for some reason the user desires not to receive a call at a certain time. The voice messages are stored in pre-assigned storage locations typically referred to as "voice mailboxes". A message switching center is generally employed for controlling the forwarding of the voice messages to the user terminal from the voice mailbox. Typically, a user of a terminal can retrieve voice messages stored in a particular voice mailbox by operating a keypad of the terminal to enter appropriate information into the terminal. By example, the user may retrieve the voice messages stored in a particular voice mailbox by depressing multiple predetermined keys of the keypad to specify an appropriate access code for the voice mailbox, or by depressing a single predetermined one of the keys of the keypad which causes the terminal to automatically dial the access code. In either case, the terminal responds to this information by communicating with the message switching center to retrieve the messages from the voice mailbox. Thereafter, the messages are provided to the user.
At least some conventional cellular systems include both public networks (or systems) and private or autonomous networks (or systems). Autonomous networks include private and residential networks, and provide service to users located within a small, generally confined geographical area such as, for example, a house or a building. Public networks provide service to users located within a large geographical area relative to the area serviced by a private network.
At least some conventional networks provide a convenient mechanism whereby a user of a user terminal can be notified if there are one or more messages stored in a particular voice mailbox upon the terminal becoming registered with a network. This is accomplished by providing a notification message from the message switching center of the network to the user terminal, in response to the terminal becoming registered with the network. By example, in response to a user terminal registering with the network, the message switching center may provide a Message Waiting indicator (MWI) message to the terminal, in accordance with standard IS-136 section 6.4.3.8. The MWI message indicates that there are messages stored in the voice mailbox. The messages stored in the voice mailbox can be retrieved by the user by operating the user terminal in the manner described above. For example, assuming that the terminal is preprogrammed to access a particular voice mailbox within a public network in response to the user depressing a specific, single key of the terminal keypad, the user can retrieve messages stored in this voice mailbox by simply depressing this single key.
Unfortunately, however, conventional user terminals do not have the capability of automatically determining which network the terminal is registered with in response to a user of the terminal requesting that messages be retrieved from a voice mailbox, so that the terminal can automatically access messages in the voice mailbox of the network with which the terminal is registered. As a result, a user may be required to enter specific access codes into the terminal when attempting to retrieve messages from voice mailboxes within particular networks. As can be appreciated, this may be burdensome to the user.
It can be appreciated that it would be desirable to provide a user terminal which overcomes this problem.